TUTORIAL ANSWERS 474-510
 
 
 


Correct answer to 474 (a):  1000=103, so log(1000)=3.
 
 Return to Question 474.


 

Correct answer to 474 (b):  Look up in the table or on the log chart. log8=0.903
 
  Return to Question 474.


 

Correct answer to 474 (c):  From table or chart, Log(4.8)= 0.681
 
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Correct answer to 474 (d) :  Find the log of 3.5 first and combine with the power of ten. 3.5 x 10-2 = 100.54 10-2 = 100.54 - 2 = 10-1.46 . So log (3.5 x 10-2) = -1.46
 
 Return to Question 474.

 
Correct answer to 474 (e) :  2000 = 2x103=100.3+3. Log(2000) = 3.3
 
 Return to Question 474.


 

Correct answer to 474 (f):  500,000= 5x105= 100.70+5. Log(500,000) = 5.70
 
 Return to Question 474.


 

Correct answer to 474 (g):  Log(2.1x10-2x 4.0 x 106) = Log (8.4x10-2+6) = Log(100.92+4)) = 4.92
 
 Return to Question 474.


 

Correct answer to 474 (h): 0.00032 = 3.2x10-4 and Log(3.2x10-4) = Log(3.2) -4 = 0.505 - 4 = -3.49.
 
 Return to Question 474.


 

Correct answer to 474 (i):  Log (438x105) = Log(4.38x102x105) = Log(4.38)+7=0.64+7=7.64
 
 Return to Question 474.


 

Correct answer to 474 (j):   It is easiest to divide first: 5x10-3/2x103 = 2.5x10-6= 100.398-6 = 10-5.6. So Log (...) = -5.6.
 
 Return to Question 474.

 

 

Correct answer to 476 (a):  10x by the definition of a logarithm as the exponent in the power of ten.
 
 Return to Question 476.


 

Correct answer to 476 (b): 102 = 100.
 
  Return to Question 476.
 


 

Correct answer to 476 (c):  104.8= 100.8x104 = 6.3 x104 by use of the log table or chart.
 
  Return to Question 476.
 


 

Correct answer to 476 (d):  100.5 = 3.2 from the table.
 
  Return to Question 476.
 


 

Correct answer to 476 (e):  10-0.5 = 1/ 100.5 = 1/ 3.16 = 0.316
 
  Return to Question 476.

 
 


 
 
 Correct answer to 476 (f): 10-16.5 = 10-17 + 0.5= 100.5x10-17 = 3.2x10-17
 
  Return to Question 476
 

 
Your answer to Q500: Sorry, your answer is not correct, please try again or click HERE to see the solution.

Help: Fundamentals of Sound, Sec. 11-E.

Return to Question 500.

 

Correct Answer to Question 500:  The correct answer is c). Multiply out the numbers to get 6 x 108 = 10(log(6) + 8), so that a) is correct. Alternatively express each number as a power of ten: 3 x 103 x 2 x 105 = 10log(3)x103x10log(2)x105 = 10(log(3) + 3 + log(2) + 5) so that b) is also correct.

Return to Question 500.

 

 
 

 
Your answer to Q510:  Sorry, your answer is not correct.  Please try again or click HERE for the solution.

Help: Fundamentals of Sound, Sec. 11-F.

Return to Question 510.

Correct Answer to Question 510:  All forms are correct so d) is the answer. 0.00063 = 6.3x10-4 so that b) is correct. But 0.00063 = 10log(6.3)x10-4 = 10(log(6.3) -4), which proves c). Next log(6.3) = 0. 8 so that log (0.00063) = 0.8-4 = -3.2 proving a).

Return to Question 510.

 

 


 


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